Rotary toothbrush with lip guard



D. P. GROVER ROTARY TOOTHBRUSH WITH LIP GUARD Filed Nov. 3, 1950 July 9,1957 i l ll v ll- United States Patent Ojfiice 2,798,237 Patented July9, 1957 ROTARY TQOTHBRUSH WITH LIP GUARD V Donald P. Grover, Chicago,Ill. Application November 3, 1950, Serial No. 193,341

4 Claims. (Cl. 15-23) This invention relates in general to rotarytoothbrushes adapted to be operated by a source of electrical or otherenergy and, particularly, to a type of rotary toothbrush adapted forpersonal use as distinguished from those commonly used by dentists. Thepresent application is a continuation-in-part combining subject matterdivided out of my earlier filed co-pending applications, Serial No.691,273, filed August 17, 1946, and Serial No. 691,979 filed August 21,1946 now Patents Number 2,533,106 and 2,533,107, respectively.

Various forms of electrically or power driven rotary toothbrushes havebeen developed heretofore, but for various reasons have found littlefavor with the public in general. One of the disadvantages of theearlytype of rotary toothbrush was the absence of any shield partiallysurrounding the brush element whereupon the rotation of the brush causedsome of the toothpaste thereon to be thrown oil and splattered about andpermitted the brush to contact the soft inner portions of the mouthcausing irritation thereof.

A later development introduced a shield which extended lengthwise of andpartially surrounded the rotating brush element, thus successfullypreventing the splattering of toothpaste, and constituted an attempt,also, the protect the lips and soft portions of the mouth from beinglacerated by the rotating brush. Actual usage of this type of rotarytoothbrush, however, disclosed that the shield was unsatisfactory as alip guard because the lip of a user tended tobe drawn inwardly againstthe bristles of the brush and between the bristles and the edge of theshield when the brush was placed against the teeth.

By means of the present invention, as well as those co-pendingapplications referred to hereinabove, the aforementioned disadvantagesof the earlier types of rotary toothbrushes have been, overcome and thelip of a user has been successfully prevented from being drawn inwardlybetween the rotating brush and the edge of the shield.

It is, therefore, a principal object of the present invention to providea power driven rotary toothbrush having a novel form of guard means toprevent the lip of a user from being pulled or drawn inwardly betweenthe bristles of abrush element and the edge of a shield during rotationof the brush.

Another object of the invention is to provide a rotary toothbrushwherein a plurality of guard members are spaced along the length of thebrush element and extend between the bristles on the brush, therebyeffectively to prevent the lip of a user from being drawn inwardlyagainst the brush during rotation thereof.

A further object of the invention is to provide a rotary toothbrushhaving a handle portion thereon wherein guard supporting means extendlongitudinally of the handle portion and are provided with individualguard members spaced along the length thereof and extending between thebristles of the brush element from the upper edge of the guardsupporting means, whereby the lip of a user is etfectively preventedfrom being drawn inwardly between the guard supporting means and thebristles of the rotating brush element.

Still another object of the invention is to provide a rotary toothbrushhaving a shield, or other suitable form of guard supporting means,extending lengthwise of the toothbrush handle at one end thereof,wherein guard members extend transversely of the shield or guardsupporting means and are spaced apart along the length thereof adistance of approximately 7 inch, or less.

A still further and more specific object of the inventionis to provide arotary toothbrush, wherein guard supporting means are provided at oneend of a handle portion and extend longitudinally thereof on oppositesides of a rotating brush spindle and wherein individual guard membersin the form of solid partitions extend transversely of the brush spindleand therebelow and are spaced along the length of the guard supportingmeans.

A still further specific object of the invention is to provide a rotarytoothbrush wherein guard supporting means extend lengthwise of a handleportion on opposite sides of a rotating brush spindle, and wherein aplurality of thin elongated lip guard members extend between the sidesof the guard supporting means and below the brush spindle, and arespaced along the length of the guard supporting means, thereby toprevent the lip' of a user from being drawn inwardly between the guardsupporting means and the bristles of the rotating brush element.

Other objects and advantages of the invention will become apparent uponreading the following description taken in conjunction with theaccompanying drawing in which:

Fig. 1 is a perspective view of the handle portion illustrating theshield thereon and one form of lip guard which may be used in connectiontherewith;

Fig. 2 is a vertical transverse sectional view through the shield andbetween adjacent lip guards;

Fig. 3 is a plan View with pants broken away and shown in section of thehandle portion and shield, but illustrating a modified form of lip guardmembers;

Fig. 4 is a vertical longitudinal section through the device of Fig. 3showing the brush element in place;

Fig. 5 is a perspective view of the device shown in Figs. 3 and 4showing the brush spindle and shield in vertical section; and

Fig. 6 is a vertical sectional view taken along line 66 of Fig. 4.

Briefly described, the invention herein consists primarily in theprovision of guard means against which the lip of the user of a rotarytoothbrush will ordinarily bear during the use thereof to guide ordirect the lip to the outer side of the shield or guard supporting meansand thus prevent the lip from being drawn inwardly between the shield orguard supporting means and the bristles of the rotating brush. When therotary brush is in use and placed against the teeth, the brush elementis usually designed to rotate in a manner to brush the teeth away fromthe gums which is considered by dentists as the proper way to brushteeth' In actual practice where no lip guards are present, it has beenfound that brushes of this character in the prior art have a tendency toirritate or lacerate the soft fleshy mouth parts, and if a shieldispresent the irritation and laceration is caused by the tendency of thebrush to pull these soft fleshy mouth parts between the brush and theedge of the shield. Serious injury to the lip and to the fleshy innerportions of the mouth may result, but if the injury is not serious it isdecidedly an unsatisfactory and unpleasant experience therebydiscouraging further use of the toothbrush. The resulting rawness andbleeding of the lacerated lips and fleshy inner portions of the mouthare considered to be the principal reasons for the lack of commercial,success of earlier rotary toothbrushes.

It will'be apparent that'numerous specific forms of guard meansmay bedesigned-to accomplish the main purpose of this invention and some ofsuch forms have been disclosed and claimed in my above referred toearlier filed co-pending applications. The inventon herein discloses, inaddition to the foregoing, twomore -specificembodiments of theinvention.

The present inventionutilizes individual guard-mem bers relative to thebr-ushspindle, is intended to indicate that the guard members pass belowthe spindle when the toothbrush is held so that the-closed side of the.shield is disposed downwardly, as illustrated particularly in Figs. 1, 4and 5.

Referring now more particularly'to the drawing, and espccially'to theform of the invention shown in Figs. 1 and 2, the main body or handleportion 1 may assume any desired shape and size, but preferably itshould be of a size convenient to be held in the hand and should beformed of a plastic or other similar and suitable nonconductingmaterial. Broadly speaking, the handle portion may embody its ownelectric motor to drive the shaft therein, or the shaft may extendthrough the handle portion and be driven from an external source. Thespecific form of the invention as disclosed herein contemplates the useof a rotatable shaft within the handle which may be easily connected toa flexible shaft for purposes of driving the brush. The handle portion 1is provided with a suitable longitudinal opening therethrough adapted tohave rotatably mounted therein a shaft which at one end thereof ispreferably provided with a slot 2 adapted to receive one end of acorrespondingly shaped spindle from which bristles extend to providethereupon a brush element. The brush spindle 3 may be of any suitableand conventional form of shaft and may be rotatably mounted in asuitable bearing in the outer upturned end 4 of a shield generallyindicated at 5. The brush element has not been shown in Figs. 1 and 2 inorder that the lip guard members may be more clearly seen, but thedotdash line 6 in Fig. 2 illustrates generally the outline of the brushbristles.

The shield may be formed separately and secured to the handle portionand may be formed as an integral part thereof, as shown in Fig. l. Theshield portion has preferably a curved bottom part 7 and upwardly turnedsides terminating in the longitudinal guard supporting edge portions 8and 9. It will be apparent that if for any reason the shield as suchcould be omitted, then other suitable guard supporting means extendinglongitudinally from one end of the handle portion could be provided totake the place of the upper longitudinal opposed edges 8 and 9 of theshield 5.

The guard members shown in Figs. 1 and 2 constitute a plurality of solidpartitions 10 which extend transversely of the brush spindle 3 andbetween the guard supporting portions 8 and 9 of the shield and arespaced apart along the length of the shield, as shown in Fig. 1. It willbe noted that each end of each partition 10 extends upwardly from thesupporting edges 8 and 9 and are then curved inwardly in a substantiallyradial direction. The upper edges of these guard members 10 then arecurved downwardly to pass below the brush spindle 3. This construction,wherein the guard members pass below the brush spindle, is efiective topermit removal and replacement of the brush element and cleaning theguard members and shield.

It has been found in actual practice that the spacing between the guardmembers is critical to the extent that if they are spaced apart too farthey will not be eflfective inpreventing the lip from being drawninwardly between the shield and the bristles of the rotating brush. Thatis to say, if these guardmembers were spaced apart a distance as greatas inch or /2 inch this distance would;

be sufiiciently great to still allow the brush to pull the lip or othersoft fleshy portions of the mouth into the shield between the guardmembers. On the other hand, these guard members or partitions must bespaced apart far enough to permit the bristles of the brush to passtherebetween. Actual practice has proven that the maximum distance theindividual guard members can be separated and still effectively preventinjury to the lip is approxi- 3 mately 7 inch. The guard members mayobviously be located closer together than this maximum limit, but it hasbeen illustrated that approximately A is about the minimum spacementwhich can be permitted and still allow the brush bristles to passbetween the guard members and effectively clean the teeth.

It will thus be evident from the foregoing that regardless of thedirection of rotation of the brush if it is placed against the teeth sothat the brush will rotate in a direction to brush the teeth away fromthe gums, any tendency for the brush to draw the lip of the userinwardly between the edge of the shield and the rotating bristles willbe prevented by the outer edges of the guard members 10 which will guidethe lip outwardly over the edge of the shield thereby preventing anydamage thereto.

The form of the invention illustrated in Figs. 3 to 6, inclusive,embodies similar features described above with respect to Figs. 1 and 2except that the individual guard members are formed of thin elongatedmembers rather than partitions. In this latter form of the invention ahandle member 11 is provided with a longitudinal opening 12 adapted toreceive a rotatable shaft 13. One end of the opening 12 is provided witha bearing 14 and the opposite end has a similar bearing 15 thereby torotatably support the shaft 13 at each end thereof. The rear or outerend of shaft 13 may be provided with a transverse rib 16 adapted to bereceived in a suitable opening or socket or flexible shaft (not shown)for purposes of driving the brush. The rear of the handle may also beprovided with radially extending ribs 17 securely to hold the end of theflexible shaft in place.

.The rear end of opening 12 is enlarged slightly as indicated at 18 andthe shaft 13 is provided wifli an annular groove 19 adapted to receive aretaining ring 20. This ring is received partially in the groove 19 andpartially in the enlarged portion 18 of the opening 12, whereby alongitudinal sliding movement of the shaft 13 may take place when it isnot connected for use in order that the. brush element may be removedtherefrom as will presently be observed.

A shield 21 or other suitable supporting means may be provided at theforward end of the handle 11 and may be integral therewith, or otherwisesuitably secured thereto in the same manner described above with respectto Fig. 1. The shield 21 extends longitudinally'of the brush element andpartially surrounds it as shown. Forward end of shield 21 has anupwardly extending end 22 having an opening at the inner side thereof toreceive a bearing member 23.

The brush spindle or shaft 24 has radially extending bristles 25 thereonand is adapted to have one end thereof received within the bearing 23.The other end of the spindle 24 is provided with a transverse rib 26adapted to. be received within a transverse slot 27 in the outer end ofshaft 13. It will thus far be evident that when shaft 13 is connected toa flexible shaft which is, in turn, connected to a source of electricalenergy for rotation, shaft 13 will be urged forwardly and rotatedthereby to rotate the brush element with it. When it is desired toremove the brush element for replacement or for cleaning, shaft 13 maybe moved rearwardly to disengage the slot 27 at the front end thereoffrom the rib 26 on the brush spindle 24 and thereupon permit the brushelement to. be bodily removed. It may be stated here that the sameconstruction in detail may be utilized in connection with the form ofthe invention shown in Figs. 1 and 2.

.The guard members in this modified form p f the invention consist ofelements 28 which may be formed integral with or rigidly secured to theupper longitudinal edges of shield 21. These elements 28 may be termedbars which are so shaped lengthwise as to curve upwardly at each endthereof from the longitudinal edges of the shield 21 and then downwardlyand inwardly to pass beneath the brush spindle 24. It will be apparentthat since these bars 28 are shaped similarly to the upper edges of thepartitions in the form shown in Figs. 1 and 2, they will act in the samemanner effectively to prevent the lip of a user from being drawninwardly be tween the shield and the bristles of the rotating brush. Thebars 28 may be formed of any suitable material, such as plastic, or maybe molded at an integral part of the shield, or may be formed of thinwire and secured to the longitudinal edges of the shield as shown.

It will be noted that in both forms of the invention the guard membersextend below the brush spindle, thereby permitting removal of the brushfrom the handle portion without disturbing the guard members. Here againthe maximum spacement between the guard members 28 is critical andshould not be more than approximately inch to obtain the most effectiveresult. The greater the spacement between the guard members the greaterwill be the possibility that some small portion of the lip or otherfleshy soft portions of the mouth contacted may be drawn inwardlybetween the spaced guard members. A space of approximately inch, orless, will effectively prevent this.

From the foregoing description it will be apparent that the presentdevice embodies certain novel forms of lip guards for use in connectionwith rotary toothbrushes, all of which will effectively prevent injuryto the lip and fleshy portions of the mouth of a user. As statedpreviously, the brush is intended to be used in such a way that rotationof the brush element is away from the gums. If the toothbrush isconstructed so that the brush element always rotates in the samedirection, then the lip guard in any case may be located on only oneside thereof. Thus, the lip guards disclosed herein may be dispensedwith along one side of the brush element without departing in any wayfrom the spirit of the invention. The provision of lip guards along bothsides of the rotating brush element may be necessary, however, ifsuitable mechanism is provided to reverse the direction of rotation ofthe brush.

From the foregoing it will be evident that a novel improvement in theart of rotary toothbrushes has been provided wherein suitable guardmeans effectively prevent the lip or fleshy soft portions of the mouthcontacted of a user from being drawn inwardly against the brush oragainst the shield and the brush element when such a shield is used. Itwill also be clear that if it is desired to omit the shield, then othersuitable guard supporting means may be utilized in its place.

Changes may be made in the form, construction and arrangement of partsfrom those disclosed herein without in any way departing from the spiritof the invention or sacrificing any of the attendant advantages thereof,provided, however, that such changes fall within the scope of the claimsappended hereto.

The invention is hereby claimed as follows:

1. A rotary toothbrush of the class described, comprising a handleportion having a rotatable shaft extending therethrough, a bruh elementconnected to one end of said shaft and rotatable therewith, a shieldpartially surrounding said brush element, and a plurality of guardmembers on said shield extending transversely thereof and spaced apartalong the length thereof a distance of approximately inch or less,thereby to prevent the lip of a user from being drawn inwardly betweenthe shield and the brush element during rotation thereof.

2. A rotary toothbrush of the class described, comprising a handleportion having a rotatable spindle extending therethrough, a brushelement connected to one end of said spindle and rotatable therewith, ashield extending lengthwise of and partially surrounding said brushelement, and a plurality of partitions spaced apart approximately inchor less extending transversely of said shield between the bristles onsaid brush element, to prevent the lip of the user from being drawninwardly between the shield and the brush element during rotationthereof.

3. A rotary toothbrush of the class described, comprising a handleportion having a rotatable shaft extending therethrough, a brush elementincluding a brush spindle connected to one end of said shaft androtatable therewith, guard supporting means extending axially of saidhandle portion on opposite sides of said brush spindle, and a pluralityof partitions extending between said guard supporting means and spacedalong the length thereof, at least a portion of the upper edges of saidpartitions passing below said brush spindle, whereby the lip of a userwill be prevented from being drawn inwardly between said guardsupporting means and said brush element during rotation thereof.

4. A rotary toothbrush of the class described, comprising a handleportion having a rotatable shaft extending therethrough, a brush elementincluding a brush spindle connected to one end of said shaft androtatable therewith, guard supporting means extending axially of saidhandle portion on opposite sides of said brush spindle, and a pluralityof partitions extending between said guard supporting means and spacedalong the length thereof a distance of approximately 31 inch or less,the upper edges of said partitions passing below said brush spindle,whereby the lip of a user will be prevented from being drawn inwardlybetween said guard supporting means and said brush element duringrotation thereof.

References Cited in the file of this patent UNITED STATES PATENTS

